Wireless communication systems are known to include a plurality of communication units, a limited number of wireless communication resources, and a communication resource controller. A typical communication unit, which may be a mobile radio, portable radio, or radio/telephone, offers its user a variety of features, such as group calls (i.e., one-to-many communications), telephone interconnect calls (i.e., one-to-one communications), and data communications. To access one of these services, the user must request access to one of the limited number of wireless communication resources and specify the type of service requested. This request is sent from the communication unit to the communication resource controller via a control channel, wherein the control channel is one of the communication resources that has been selected to function as the control channel. Upon receiving the request, the communication resource controller determines whether this particular communication unit is authorized to access the requested service and, if so, whether a communication resource is available for allocation. When both conditions are positive, the communication resource controller allocates a communication resource to the requesting communication unit such that the user can access the requested service.
In addition to allocating a communication resource, the communication resource controller may also need to establish a communication path within a public data communication interconnect system, such as a public switch telephone network (PSTN), to complete the service request. For example, if the requested service is for a data communication, in which the user is requesting that a data file be transferred to it via the wireless communication system, the communication resource controller would need to allocate a wireless communication resource to the requesting communication unit and also establish a wireline communication path with the holder of the requested data file via the public data system. Once both of these communication paths (i.e., the wireless path and the wireline path) have been established, the requested data file can be transferred to the requesting communication unit.
The above described data transfer is becoming more and more common as technological advances occur in both the wireless art and the wireline art. These technologic advances are allowing more data to be transferred in less time via data compression, time division multiplexing, quadrature amplitude modulation techniques, ADSL, MPEG standards, ISDN, and spread spectrum techniques. As the amount and frequency of data transmissions increase, so does the chance for illicit transmissions of the data. Illicit transmissions of data, which may include video data (i.e., movies), audio data (i.e., music or conversations), data files (e.g.. police files, books, etc.), occur when a transceiver has an unauthorized copy of data for transmission or transmits authorized data to an unauthorized receiver.
In a typical wireless communication system, unauthorized reception of data is limited by addressing appropriate receiving communication units and instructing them, via the control channel, to affiliate with another communication resource to receive the data transmission. Even though all the communication units within range of the control channel's antenna receive the addressing information, only the communication unit or units that are addressed will affiliate with the communication resource. In an ideal system (i.e., one without units illicitly receiving data transmission), only the authorized communication units receive the requested data. Unfortunately, there are few, if any, ideal systems left, thus illicit reception is a real and serious problem costing the owners of the data millions of dollars in lost revenue.
One solution that reduces illicit receptions is to encrypt the data. Encryption may be a simple encryption algorithm or a complex algorithm. If a simple algorithm is used, e.g. adding an offset to the data, it can be easily decrypted, thus allowing illicit reception. While the complex algorithms are more difficult to decrypt, which prevents unauthorized reception, there is a considerable amount of overhead and complexity which slows the data transfer rate. In addition, wireless communication units do not have a mechanism to determine whether incoming data is sensitive or not. Thus, the communication unit uses whatever encryption/decryption algorithm that is currently loaded to encrypt/decrypt communications, which, for some communications is overkill and for others, jeopardizes its security. Also, there is currently no mechanism that determines whether a proper security level is being used or whether such data should even be transmitted due to its sensitive nature.
Therefore, a need exists for a method and apparatus that prevents illicit wireless data transmissions based on the sensitivity of the data being transmitted and insures that the proper security level is used.